(Could the title of this thread please be fixed? "Veered of course towards the US" is a bit misleading. Unless, off course, it was a politically motivated action...)

I merely paraphrased what was in the original article I posted.

I believe the suggestion was to change the title to"British Trident missile tests veered off course towards the US"

My emphasis shows the change that was intended [I believe].

"veered of course towards the US" means the Royal Navy deliberately fired at the US.while"veered off course towards the US" means the missile headed in the wrong directionwhich I believe was the thrust of the original article and this thread.

While I'm at it "tests" in the title should also go to the singular since we're only talking about one missile in the June 2016 incident.

The missile was converted into a test configuration using a test missile kit produced by Lockheed Martin that contains range safety devices and flight telemetry instrumentation.

So is it only under test conditions they can terminate a flight?

If you had to launch these missiles for a nuclear war, you don't want your opponent to be able to terminate the flight. It doesn't get more serious than nuclear deterrence and you can't risk espionage neutralizing your missiles.

It made me think about something I hadn't before. As with any system, and especially rockets, we know there must be some failure rate. Does anyone know or have information regarding the expected/worst case failure rate in a full system deployment? Ie: if we somehow got to nuclear holocaust, how many would've never left our shores?

It made me think about something I hadn't before. As with any system, and especially rockets, we know there must be some failure rate. Does anyone know or have information regarding the expected/worst case failure rate in a full system deployment? Ie: if we somehow got to nuclear holocaust, how many would've never left our shores?

better than 90%. The warheads won't go off during launch failures. Interlocks based on air pressure and acceleration and deceleration will prevent it.

It made me think about something I hadn't before. As with any system, and especially rockets, we know there must be some failure rate. Does anyone know or have information regarding the expected/worst case failure rate in a full system deployment? Ie: if we somehow got to nuclear holocaust, how many would've never left our shores?

No one knows. The number of strategic delivery systems able to response to an authenticated strike order depends on several factors. First someone have to be able to issue the order. Second the order have to be transmitted to a launch facility. Third the delivery system have to be able to launched. Fourth the delivery system have to withstand possible counter-measures post-launch and transit to to target. How many delivery systems one side think can get to them from the other side is the level of perceived deterrence for the other side.

Strategic missiles are only a variable deterrence if periodically demonstrated to be functional in all phases of operation. Of course minus the warhead. A fail launch like the Trident will reduce the perceived thread from that delivery system.

P.S. Think Jim is much more optimist than me in the number of delivery systems able to response to a strike order.

It made me think about something I hadn't before. As with any system, and especially rockets, we know there must be some failure rate. Does anyone know or have information regarding the expected/worst case failure rate in a full system deployment? Ie: if we somehow got to nuclear holocaust, how many would've never left our shores?

No one knows. The number of strategic delivery systems able to response to an authenticated strike order depends on several factors. First someone have to be able to issue the order. Second the order have to be transmitted to a launch facility. Third the delivery system have to be able to launched. Fourth the delivery system have to withstand possible counter-measures post-launch and transit to to target. How many delivery systems one side think can get to them from the other side is the level of perceived deterrence for the other side.

Strategic missiles are only a variable deterrence if periodically demonstrated to be functional in all phases of operation. Of course minus the warhead. A fail launch like the Trident will reduce the perceived thread from that delivery system.

P.S. Think Jim is much more optimist than me in the number of delivery systems able to response to a strike order.

Since the topic is about a Trident veering off course, the pertinent question is the success rate of missiles launched. Failures in tests like these are rare, so a 90% success rate sounds reasonable.

In a response situation, as you wrote, how many missiles are able to be launched would be a much lower number.

It made me think about something I hadn't before. As with any system, and especially rockets, we know there must be some failure rate. Does anyone know or have information regarding the expected/worst case failure rate in a full system deployment? Ie: if we somehow got to nuclear holocaust, how many would've never left our shores?

Jim's estimate of 90% sounds about right for modern systems. Older systems, not so much. If you haven't already read it, I would strongly recommend the book Command and Control by Eric Schlosser. Among other things, it dives into how weapons readiness and availability was exaggerated, especially during the early years of the Cold War. The SM-62 Snark in particular had absolutely abysmal reliability.

It made me think about something I hadn't before. As with any system, and especially rockets, we know there must be some failure rate. Does anyone know or have information regarding the expected/worst case failure rate in a full system deployment? Ie: if we somehow got to nuclear holocaust, how many would've never left our shores?

better than 90%. The warheads won't go off during launch failures. Interlocks based on air pressure and acceleration and deceleration will prevent it.

Agreed. I would go so far as to expect a 98% or better missile launch rate success. This is based on the flight history of Tridents and Minutemen over the years, and it includes performance right down to the target. Warhead failures might add a percent or two.

I've read about people, non-military types, who took detailed, hard looks at these systems - who looked at the missiles and watched them fly. They shuddered when they realized - for certain - that it all wasn't a mirage. This stuff will all actually work with horrifying effectiveness. Not just the U.S. systems, but the Russians and others as well.

There's something simultaneously reassuring and worrisome about a rarely tested nuclear deterrent delivery system that might just cartwheel hilariously in its individual units and not make any significant contributions to doomsday, despite the overwhelming effectiveness of the system at large.

I can assume US, UK and French ballistic missile reliability is slightly ahead of any foreign counterparts that might prospectively be lobbing missiles back at them. Would be (academically) interesting to see the failure margin if such a - catastrophic - event was ever to occur. On such an occasion, how many missiles would experience launch failures? Twenty? Fifty?

There's something simultaneously reassuring and worrisome about a rarely tested nuclear deterrent delivery system that might just cartwheel hilariously in its individual units and not make any significant contributions to doomsday, despite the overwhelming effectiveness of the system at large.

They aren't "rarely" tested. There have been over 150 Trident II test flights..

I can assume US, UK and French ballistic missile reliability is slightly ahead of any foreign counterparts that might prospectively be lobbing missiles back at them. Would be (academically) interesting to see the failure margin if such a - catastrophic - event was ever to occur. On such an occasion, how many missiles would experience launch failures? Twenty? Fifty?

On such an occasion, how many missiles would experience launch failures? Twenty? Fifty?

Less than 5%

And to mitigate any potential failures (or intercepted missiles, bombers, etc.), the US nuclear targeting strategy (and presumably that of other nations, as well) involves a fair bit of overkill, with virtually every significant target assigned multiple warheads to ensure its destruction.